Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Isospora”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 181 records · Page 10Linked to original sources
PubMed1987

Isospora belli and Cryptosporidium sp. from a patient not suspected of having acquired immunodeficiency syndrome.

Several protozoa including Cryptosporidium sp. and Isospora belli were found in a stool specimen from a patient not suspected of having Acquired Immunodeficiency Syndrome (AIDS). As a result of the parasitologic findings, serologic tests were ordered that verified the diagnosis of AIDS. All stool specimens are routinely tested for presence of acid fast organisms with a modified acid fast technique.

Adult↗
PubMed1976

Development of Isospora begemina in dogs and other mammals.

The life-cycle of canine Isospora bigemina was studied in dogs, cattle, cats and mice. Under experimental conditions dogs served as both definitive and intermediate hosts. Unsporulated oocysts (11 X 12 mum) were shed in the faeces and sporulated outside the host within 12 h at 30-37 degrees C and 36 to 48 h at 23 degrees C. Sporulated oocysts measured 12 X 13 mum and contained 2 sporocysts which in turn contained 4 sporozoites. Sporocysts averaged 6 X 9 mum and sporozoites averaged 2 X 6 mum. Although no stages were found microscopically in tissues or in faeces of 23 dogs orally inoculated with sporulated oocysts, the oocysts were infectious because 5 of 14 dogs that ingested tissues of dogs fed oocysts, shed oocysts. Prepatent periods were 7 to 15 days; patency was 1-3 days. No dogs became ill. In the naturally infected dog and one experimentally infected dog, schizonts were found in epithelial cells, distal to the host cell nucleus at the tips of villi throughout the small intestine. Schizonts were 5-7 mum and contained 3-12 merozoites. In the naturally infected dog, gametes were found in the same location. Male gametocytes were 6-8 mum and contained 6-12 microgametes, and female gametes were 7-8 mum. Sporulated I. bigemina oocysts from a naturally infected dog were not infectious to cattle, cats or mice. Structurally identical oocysts were shed by 2 dogs after ingesting hearts and diaphragm from naturally infected cattle; these oocysts were also not infectious to cattle. Although dogs acted as both intermediate and definitive hosts under experimentation, this is not likely to occur in nature. A canine-bovine-canine cycle would appear to be the natural mode of infection but I. bigemina was not infectious to cattle under experimental conditions.

Animals↗
PubMed1985

Sex determination and sex differentiation in coccidia: gametogony and oocyst production after monoclonal infection of cats with free-living and intermediate host stages of Isospora (Toxoplasma) gondii.

Clones of single oocysts, single sporocysts, single sporozoites, single proliferative parasites, single cysts and single cystozoites of Isospora (Toxoplasma) gondii (KB-strain) were made under visual control using a de Fonbrune micromanipulator. Cloning was successful in 28, 32, 21, 8, 54 and 7% of the trials, respectively. All clones were used for monoclonal infection in non-immune conventionally reared (CV) or specified pathogen-free (SPF) cats. Pre-patent and patent periods, sporulation percentages of excreted oocysts, mouse infectivity of sporulated oocysts, antibody response and immunity to reinfection of CV cats were determined. For these parameters almost no differences were observed between monoclonal infections and infections described with the non-cloned KB-strain. In all cats autopsied during the patent period, 5-8 days post-infection, macrogametes, microgametes and oocysts were found. Since meiosis occurs during sporulation and since all free-living and intermediate host stages proved to be bisexual, it is concluded that sex differentiation in I. (T) gondii is not determined by segregation of sex chromosomes or sex genes but is caused by some final host factor(s) that induce(s) differential gene expression in genetically identical cells.

Animals↗
PubMed1984

Cytochemical studies on nuclear DNA of four eucoccidian parasites, Isospora (Toxoplasma) gondii, Eimeria tenella, Sarcocystis cruzi and Plasmodium berghei.

Feulgen-pararosaniline (SO2) staining was performed on stages in the life-cycle of Isospora (Toxoplasma) gondii, Eimeria tenella, Sarcocystis cruzi and Plasmodium berghei. The fluorescence emission of the stained DNA in nuclei of these stages was examined and compared with absorption microscopy measurements at 560 nm (green light) of the same specimens. Accurate identification of single cells, and especially discrimination between young schizonts and young gamonts was difficult after Feulgen staining. To overcome this problem preparations were first stained with Giemsa and the cells of interest precisely located with the aid of an England finder. The same preparations were then hydrolysed and stained with Feulgen-pararosaniline (SO2), after which the previously identified cells were investigated. The DNA distribution after Feulgen staining corresponded with the shape of nuclei after Giemsa staining. DNA was present in all investigated stages of the four parasites, including macrogamonts of I. (T.) gondii and E. tenella and peripheral blood gamonts of P. berghei. Macrogamonts could be recognized, even at a stage at which they can hardly be differentiated from young schizonts in Giemsa-stained preparations, by their typical distribution pattern of Feulgen fluorescence. Feulgen fluorescence was more granular and confined to the peripheral region of the nucleus, leaving a distinct nucleolus unstained. The horseshoe-shaped nuclei typical of macrogamonts could also be observed in some second generation merozoites of E. tenella, indicating that these merozoites are already sexually differentiated. The relationship between the present cytochemical observations and the ultrastructure of the four investigated parasites is discussed.

Animals↗
PubMed1984

Determination of nuclear DNA of five eucoccidian parasites, Isospora (Toxoplasma) gondii, Sarcocystis cruzi, Eimeria tenella, E. acervulina and Plasmodium berghei, with special reference to gamontogenesis and meiosis in I. (T.) gondii.

DNA contents of individual stages of Isospora (Toxoplasma) gondii and other Eucoccida were measured after Feulgen-pararosaniline (SO2) staining either by direct microfluorometry or by scanning of microphotographic negatives. Frequency distributions were analysed using a computer program based on a mathematical model describing cell division. All stages of I. (T.) gondii, except fertilized macrogametes (2c), contained a haploid amount of DNA (1c), indicating that meiosis in I. (T.) gondii occurs during sporogony. Microgametes possessed 3.3% DNA in excess, presumably mitochondrial DNA. Nuclei of M2- and M3-merozoites differed in two characteristics: a small but distinct nucleolus was observed in almost 50% of the M2-merozoites but in none of the M3-merozoites; all M2 merozoites were strictly haploid, while all M3-merozoites were synthesizing DNA (17% above the haploid value). It may be concluded that all M2- and M3-merozoites are already sexually differentiated, i.e. are macro- and microgamontoblasts, respectively. DNA synthesis necessary for the development of the microgamont starts already in the microgamontoblast stage (M3-merozoite). M2-merozoites macrogametes, synthesize 11% extra DNA before fertilization, (after fertilization an extra amount of 12% of the diploid value was found), probably by amplification of genes for proteins which are needed for rapid maturation and later sporogony. Essentially parallel results have been found in Eimeria tenella and in crescent cystozoites of Sarcocystis cruzi. Absolute DNA values in representatives of the Eucoccida have been estimated as follows (10(-15) g): I. (T.) gondii, 96; E. tenella and E. acervulina, both 75; S. cruzi, 216; Plasmodium berghei, 27. The value of the estimation of total haploid amounts as a tool in taxonomy of Eucoccida is discussed.

Apicomplexa↗
PubMed1989

Treatment and prophylaxis of Isospora belli infection in patients with the acquired immunodeficiency syndrome.

Enteric infection with the protozoan Isospora belli is common in patients with the acquired immunodeficiency syndrome (AIDS) and causes severe diarrhea. I. belli responds well to treatment with trimethoprim-sulfamethoxazole, but there is a high rate of recurrence. To investigate the effect of long-term prophylaxis, we studied 32 Haitian patients with AIDS complicated by I. belli infection and chronic diarrhea. All were treated with trimethoprim (160 mg) and sulfamethoxazole (800 mg), given orally four times a day for 10 days; the patients were then randomly assigned to receive 500 mg of sulfadoxine and 25 mg of pyrimethamine weekly, 160 mg of trimethoprim and 800 mg of sulfamethoxazole three times a week, or placebo. Half of the patients (5 of 10) who received placebo had recurrent, symptomatic isosporiasis a mean of 1.6 months after the initial treatment. All 22 patients who received either trimethoprim-sulfamethoxazole or sulfadoxine-pyrimethamine remained asymptomatic. I. belli was identified in the stools of only one of these patients, who was receiving trimethoprim-sulfamethoxazole. The study medications were generally well tolerated but had to be discontinued in the cases of two patients because of severe pruritus. In 10 patients, the prophylactic regimen has been continued for a mean of 16 months without recurrent isosporiasis. We conclude that isosporiasis in patients with AIDS can be treated effectively with a 10-day course of trimethoprim-sulfamethoxazole and that recurrent disease can subsequently be prevented by ongoing prophylaxis with either trimethoprim-sulfamethoxazole or sulfadoxine-pyrimethamine.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Pathogenesis of experimental combined infections with Isospora suis and rotavirus in conventional and gnotobiotic piglets.

51 gnotobiotic and 63 conventional, one-, or two-days-old piglets were divided into five groups and infected orally either with Isospora suis or rotavirus alone, or with both agents simultaneously or successively with alternative sequences and various intervals. 15 gnotobiotic and 10 conventional piglets served as controls. The development of small intestinal lesions after infection with I. suis was biphasic. The dominant alteration resulting from rotavirus infection was villus atrophy, considerably more pronounced and extensive in gnotobiotic than in conventional piglets. Synergistic action of I. suis and rotavirus was manifested both clinically, and morphologically. This action culminated at the time of the actual, or presumed development of merogony of I. suis, i.e. on DPI 3 to 5. The action develops only if the intestinal epithelium is damaged functionally and morphologically by a preceding rotavirus infection. It is concluded that the synergistic action is based on a competition of rotavirus and I. suis for mature, enzymatically active absorptive cells.

Animals↗
PubMed1978

Effect of immunization of cats with Isospora felis and BCG on immunity to reexcretion of Toxoplasma gondii oocysts.

The effect of pretreatment with Isospora felis and bacillus Calmette-Guérin (BCG) on the reexcretion of Toxoplasma gondii oocysts was studied in 16 coccidia-free cats. The following conclusions were drawn: (A) Chronically T. gondii-infected cats reexcreted T. gondii oocysts after superinfection with I. felis, and this reexcretion was prevented in cats infected with I. felis before T. gondii infection. (B) Administration of BCG before Toxoplasma infection had no apparent effect on the outcome of the infection.

Animals↗
PubMed1976

Observations on Isospora suis infection in a minimal disease pig herd.

Faeces samples from 11 sows and their litters and intestinal contents and scrapings collected from 56 piglets at the time of slaughter were examined for Isospora suis. The findings indicate that oocysts with sporoblasts can be found in faeces samples 24 hours after collection; the prepatent period is about six to nine days and the patent period three to eight days (adjudged under non-experimental conditions); piglets in an infected herd are normally resistant to natural infection for the first three weeks of life. Infection is followed by the development of an active immunity which is not affected by the stress of farrowing.

Animals↗
PubMed2000

Isospora belli infection and chronic electrolyte disturbance in a child with fetal alcohol syndrome.

We report an 11-year-old boy with fetal alcohol syndrome and immunodeficiency, whose longstanding malnutrition, diarrhoea with steatorrhoea, symptomatic electrolyte loss and eosinophilia were attributed to renal tubular disease and recurrent worm infestation. The symptoms resolved with diagnosis and treatment of infection by the protozoan Isospora belli, although immunodeficiency persisted.

Child↗
PubMed1988

Isospora belli infection: treatment with pyrimethamine.

Isosporiasis is an uncommon but important diarrheal disease of humans that, like cryptosporidiosis, is life-threatening in patients with the acquired immunodeficiency syndrome (AIDS). Isospora belli infection responds rapidly to therapy with trimethoprim-sulfamethoxazole, but patients with AIDS have a high rate of adverse reactions to this therapy. The cases of two patients with AIDS, sulfonamide allergy, and I. belli infection are reported. They were treated successfully with pyrimethamine alone, 75 mg/d, and recurrence was prevented with daily pyrimethamine therapy, 25 mg/d. In patients with AIDS with sulfonamide allergy or intolerance, pyrimethamine alone seems to be a reasonable alternative therapy for I. belli infection.

Adult↗
PubMed1991

Isospora belli infection in a patient with Hodgkin's disease: report of a case.

A 42-year-old woman with a history of documented Hodgkin's disease for 1 year presented with watery diarrhea for 6 months. She developed watery diarrhea following recurrence of the underlying disease and use of herbs. After institution of chemotherapy, watery diarrhea persisted despite remission of the underlying disease. Stool cultures and examinations for several pathogens were negative. Later, oocysts of Isopora belli were identified in the stool. The immunological status was typical of patients with Hodgkin's disease. However, HTLV-1 seropositivity and an intact skin test for delayed hypersensitivity were noted. Institution of co-trimoxazole led to prompt resolution of the gastrointestinal symptoms within the ensuing 24 hours. Later she developed recurrent isosporiasis after chemotherapy for the underlying disease, but institution of co-trimoxazole again resolved the symptoms. She remains on maintenance therapy with co-trimoxazole. Isospora belli infection should be considered in opportunistic infections in patients with Hodgkin's disease.

Adult↗
PubMed1990

[Density of selected enzymes in the goblet cells of the small intestine in piglets experimentally infected with the coccidium Isospora suis].

The density of selected enzymes in the goblet cells of the mucous membrane of the small intestine was studied in a group of 12 gnotobiotic piglets experimentally infected with the coccidium Isospora suis one day after parturition (DPP), using the Vickers M-786 scanning and integrating microdensity meter. At an infecting dose of 100,000 oocysts of I. suis, the histochemistry of the goblet cells of the mucous membrane of the piglets changed significantly in the period of 4 to 10 days after infection (DPI). Increases occur in the density of non-specific esterase (EC. 3.1.1.1.) and acid phosphatase (EC. 3.13.2.). The density of acid and neutral muco-substances declines and the densities of alkaline phosphatase (EC. 3.1.3.1.) and aminopeptidase M (EC. 3.4.11.2) are significantly high. The goblet cells of the mid and posterior parts of jejunum are very similar in their histochemistry in the experimentally infected gnotobiotic piglets. In the duodenum and ileum the histochemical picture of the goblet cells shows no substantial difference from the data recorded in the goblet cells of the mucous membrane of the small intestine of the four control piglets at an age of two to seven days.

Acid Phosphatase↗
PubMed1990

[Densitometric analysis of aminopeptidase M activity in small intestine mucosa in piglets experimentally infected with Isospora suis].

In gnotobiotical and conventional piglets infected a day post partum (DPP) with oocysts of the coccidium Isospora suis, densitometrical analysis of the activity of aminopeptidase M (EC.3.4.11.2; APM) was performed in the area of microvillous zone of the small intestine. Piglets were infected with different infection doses of oocysts (100,000 oocysts) in gnotobiotical piglets and 200,000 oocysts in conventional piglets). In infected gnotobiotical piglets, the APM activity was studied in the period from the 3rd to 11th day after infection (DAI) and in infected conventional piglets in the period of to the 2nd to 10th day after infection (DAI). Control piglets, in the group of the gnotobiotical animals at the age of 2 to 5 days in the group of the conventional animals at the age of 4 to 7 days, had different APM activity in the microvillous zone of the intestinal mucosa. It was stated that the microvillous zone of the intestinal mucosa gained higher values in control conventional piglets (+7.01 mean values of density). In infected gnotobiotical piglets the density fall of the reaction product of APM was demonstrated already on the third day with further marked reduction of APM density on the 4th day after infection in the whole small intestine with predominance of the persisting APM activity in ileum. Even despite the slight increase in the density of the reaction product of APM in the period from the 5th to 7th DAI (the highest increase in APM density on the 6th DAI), a further decrease of the activity was recorded again on the 8th and namely the 9th DAI in the whole small intestine (the lowest value of density was found in the rear jejunum), the ileum mucosa being affected, too. A slightly higher density of the reaction product of APM was found in the duodenum. On the 10th DAI the APM density started to change and on the 11th DAI in the duodenum and in the middle jejunum it even reached higher values in comparison with the control data. Some differences were proved in the infected conventional piglets in comparison with the development of the APM activity in the small intestine mucosa in the infected gnotobiotical piglets. On the 3rd and 4th DAI APM defect occurred in the whole small intestine, with APM density prevailing in the ileum mucosa (like in the group of infected gnotobiotical piglets). The second period of decrease in APM activity lasted for almost four days (6th to 9th DAI).(ABSTRACT TRUNCATED AT 400 WORDS)

Aminopeptidases↗
PubMed1990

[Histochemistry of selected peptidases in small intestine mucosa in piglets experimentally infected with Isospora suis].

In the small intestine mucosa of 24 gnotobiotical piglets experimentally infected the first day post partum with oocysts of the coccidium Isospora suis, the activities of dipeptidylpeptidase IV (EC.3.4.14.5.; DAP IV) and gamma-glutamyl transferase (EC.2.3.2.2.; GGT) in the microvillous zone of enterocytes were evaluated by scanning densitometry. The tissue of the small intestine in piglets infected with a dose of 100,000 oocysts of the coccidia of I. suis was examined in the period from the first till the eleventh day post infection (DPI). In the control piglets at the age of 2-5 days it was found that most of the DAP IV activity was located in the microvillous zone of the enterocytes of the middle jejunum, rear jejunum and ileum. The DAP IV activity of duodenum mucosa was lower; as compared with the activity in the mucosa of the jejunum and ileum it reached 53-57%. In the case of GGT activity, the highest density values of the reaction product were recorded in the microvillous zone of enterocytes of the duodenum and the whole jejunum, the lowest in the ileum mucosa (86-89%) of the activity found in the duodenum and jejunum). During the experimental infection the infected piglets had a significant deficit of both peptidases, especially DAP IV (the whole studied period). The development of GGT activity was slightly different with the onset of the marked decline of the enzyme activity only on the fifth DPI. The lower GGT activity persisted till the eighth DPI. The density of the GGT reaction product began to return to the normal on the ninth to eleventh DPI. No predisposition in the location of the deficit was observed in the peptidases studied during the infection. The decline of the activity of both enzymes influenced also the mucosa of all studied parts of the small intenstine. The difference lay in the relevance of lowering of the density of reaction product of DAP IV and GGT on other DPI and in the different intensities of the return of the activity to the physiological normal.

Animals↗
PubMed1990

[Alkaline phosphatase activity in goblet cells in the small intestine of piglets experimentally infected with the coccidium Isospora suis].

Alkaline phosphatase activity (EC. 3.1.3.1.) in goblet cells was investigated in the small intestine of 16 gnotobiotic piglets infected one day after delivery (DAD) by different rates of oocysts of Isospora suis coccidia. At a high infection rate of I. suis (750,000) the goblet cells were found to be highly positive to alkaline phosphatase on day 3 to day 4 after infection (DAI). In piglets infected by a low infection rate of I. suis oocysts (100,000) the activity of alkaline phosphatase activity in goblet cells was proved on days 4 to 10 after infection. In the first group of piglets, the positive goblet cells prevailed in the middle region of jejunum, with the peak on 4th DAI. It the second group of piglets a marked increase in the alkaline phosphatase activity was recorded in the goblet cells in the posterior part of jejunum on days 4 to 5 after infection and on 10th DAI. No alkaline phosphatase activity in the goblet cells was demonstrated in the control gnotobiotic piglets at the age of two to seven days.

Alkaline Phosphatase↗
PubMed1990

[Enteritis caused by Isospora belli in patients with the acquired immunodeficiency syndrome. Description of 9 cases].

The features of the nine first cases of Isospora belli enteritis in patients with acquired immunodeficiency syndrome (AIDS) diagnosed in the Hospital Cliníc i Provincial of Barcelona from September 1984 to May 1989 are reported. All patients were male, five were homosexual and four were parenteral drug abusers. The clinical presentation was watery diarrhea without pathological products lasting for more than one month. Five patients had features of dehydration, five had malabsorption, two had fever and one had metabolic acidosis. Enteritis by I. belli was the first opportunistic infection in eight of the nine cases. The number of T4 lymphocytes was lower than 0.4 x 10(9)/l in four of the seven patients in whom it was measured, and the p24 antigen was detected in serum in three out of five. The response to co-trimoxazole, both in the acute phase and as maintenance therapy, was satisfactory; however, two patients had recurrences despite maintenance therapy with co-trimoxazole. In one of them I. belli was clinically resistant to co-trimoxazole therapy and to other drugs, the diarrhea only responding to the administration of a somatostatin analogue (SMS 201-995).

Acquired Immunodeficiency Syndrome↗